1. Field
Example embodiments of the following disclosure relate to an image sensor having a pixel architecture for capturing a depth image and a color image, and more particularly, to an image sensor having a pixel architecture including pixels sharing a floating diffusion (FD) node.
2. Description of the Related Art
In order to capture a three-dimensional (3D) image of an object, a color image and a depth image of the object may be extracted simultaneously. Capturing a 3D image using a conventional image photographing apparatus may be difficult because the image photographing apparatus extracts only a color image of an object. As such, it may be difficult to obtain depth information from the color image alone.
To resolve such difficulties, as a method of extracting a depth image of an object, a time of flight (TOF) process by which a light may be radiated, and a TOF of the light may be verified by sensing a light reflected by the object, may be employed.
Further, a size of a pixel used in a depth camera extracting a depth image may be in a range of about 30 to 40 micrometers (μm). In addition, a size of a pixel used in a color camera extracting a color image may be in a range of about 1.4 to 3.6 μm.
In order to generate a 3D image, both the depth image and the color image may be obtained. Accordingly, in order to extract both the depth image and the color image using a pixel, it may be necessary to reduce a size of the pixel. However, when the size of the pixel is reduced, a size of a photodiode included in the pixel may be reduced, and a sensitivity of the photodiode may decrease. As the sensitivity of the photodiode decreases, a degree of precision for measuring the depth may also decrease. Accordingly, securing a maximum size of the photodiode may be necessary.